Portable electric lamp



W. A. HARVEY.

PORTABLE ELECTRIC LAMP.

APPLICATION FILED MAR. I8, 1920.

'L3SU 143, Patented May 31, 1921.

.3 SHEETS-SHEET l.

W. A. HARVEY.

PORTABLE ELECTRIC LAMP.

APPLlCA T ION FILED MAR. 15, 1920.

Patented May 31, 1921.

a SHEETS-SHEE? 2.

W. A. HARVEY.

PORTABLE ELECTRIC LAMP.

APPLICATION FILED MAR 18, 1920.

13% 1&3. Patented May 31, 1921.

3 SHEETS-SHEET -3.

entree STAT-ES JPORTAIBLE ELEGTRIC LAM mascara.

Specifieationof Letters Patent. 7 Pat t d M 31 1921 Application filed March 18, 1920. Serial No. 366,734.

., To all whom it may concern Be it known that 1, WILLIAM A. HARVEY, a citizen of the United States, and resident of Scranton, in the county of Lackawanna and State of Pennsylvania, have invented certain new and useful Improvements in Portable Electric Lamps, of which the following is a specification.

My invention relates to electric lamps, and more particularly to a type of portable electric lamps adapted to be placed upon desks, tables and the like. My lamp embodies means within itself for varying the degree of illumination supplied by the lamp.

It is desirable at all times to provide an electric lamp which may be adjusted to give different degrees of illumination, inasmuch as it is not always desirable that the lamp I have provided a lamp,

shall be bright. wherein different degrees of illumination may be obtained, and the means for changing the degrees of illumination being at all times in easy control of the user of the lamp.

My invention resides mainly in providingv a lamp fixture'having a base recessed so as to housea series of resistance elements, and also means for cuttmg in or out this res1stance. The means for controlling the cutting in and out of theresistance is placed in an accessible position, so that it is only necessary for the user of the lamp to adjust. the set screw and thereby control the degree of illumination which the lamp will give.

Another object of my invention is to provide a multi-phase lamp of this sort, in which the resistance element controlling the degrees of light is placed in the usual light circuit and does not interferein anyway with the turning on or ofi of the light.

Other objects will appear .more fully hereinafter in the specification and in the drawings, inwhich Figure 1 is'a perspective view of my portable lamp structure;

half of my invention, showing the third form Fig. 2 is a vertical section of the lower- Fig. .7 is a detailed perspective view of one portion of my invention; and

- Fig. 8 is a diagrammatic View of the cir cult arrangement thereof.

Referring now more particularly to Figs. 1, 2 and 3, Ifwill describe the various features of my invention. By referring ".to Fig. 1, it will be seen that'my fixture in its preferred embodiment comprises a base 1, and a central post 2, upon which is supported any usual type of socket 3, provided with the usual snap switch 4 for turning on or off the light. The usual lamp 5 is inserted in the socket 8, and provided with shade 6. The base 1 is recessed, as shown at 7 (Fig. 2), to provide 'a' housing space for various parts of my invention. v

This base 1 is also recessed centrally of its top base, as shown at 8, to receive projectlng end 9 of the post 2. The post 2 has a central bore 10, through which is inserted a plpe 11 The usual lead wires 12 are adapted to extend through the pipe 11 to provide electrical connection between the lamp socket 3 and the recess 7 The 11 per end of the pipe 11 is screw-threade as shown at 13, to receive the socket member 3. The lower end of this pipe 11 projects beyond the lower end of the post 2 and through the base 1 and into the recess 7. A washer 14 is placed on the lowerend of the pipe 11, and a nut 15 screw-threaded thereon. Tn'this manner the post 2 is rigidly secured to the base 1 to provide a substantially rigid connection between the two.

As clearly indicated in Fig. 2, the walls of the recess 7 are substantially covered throughout with sheet asbestos 16, for a purinsulating plate 17. This plate is screwed, as by screws 18, to thevupper wall of the recess 7, and is provided approximately centrally thereof with an aperture 19 for a purpose to be hereinafter more fully described.

Evenly disposed along one edge of the plate 17 are three spring contact members 20, 21 and 22. These members are secured to the plate17 in any suitable manner, here shown by bolt and nut 23. Contact posts 24: are also provided, so as to allow for elec trical connection thereto.

As shown clearly in Fig. 7, these spring and adjacent one side thereof, I provide an contact members have their free ends bent upwardly away from the plate 17 and superimposed one upon the other. As shown in Fig. 7, spring contact member 20 lies nearest 5 the plate 17, having directly thereover contact member 21, and contact member 22 being the uppermost one.

Secured adjacent the opposite side of the recess 7 and to the upper side thereof, I pro- 10 vide a two-part resistance element 25. I have shown this resistance element as being secured by means of a strap 26 and a screw 27.

Directly above the aperture 19 of the plate 17 and upon the top face ofthe base 1, I provide a metal strap 28, adapted to receive the screw-threaded shank 29 of an operating screw 30. The base 1 is apertured, as at 31, to provide a passage-way for the screwthreaded shank 29. An examination of Figs.

2 and 7 will indicate the relation of the operating screw 30 and the spring contact spring contacts 20 and 21, and still further 30 downward movement will cause spring contact 21 to impinge against spring contact 22, thereby causing all three spring contact members to be connected, thereby providing for the transmission therethrough of an 85 electric circuit. The upper face of contact member 20 is insulated, as shown at 31, in order to prevent the liability of a shock being transmitted to the operator. In this connection it should be stated that'the head 40 of the operating screw 30 may also be made of insulation material, to further safeguard the user from shocks due toa livecontact.

As'clearly indicated in Fig. 2, the base 1 has a series of radial holes drilled therein,

as shown at 32, to provide ventilation for the recess 7. The post 2 has bored vertically therethrough, passage-ways 33, which communicate with the recess 7 By providing these passage-ways 33 and radial holes 32, I

am enabled to efficiently ventilate the recess 7 and materially assist in the disposition of any heat which may be generated by the re sistance element 25. It should be noted that a sort of. draft is set up, by reason of the arrangement of these ventilating apertures, as air will come in through theradial holes 32 and pass outwardly through the vertical passage-ways 33. V

The bottom face of base 1 is recessed, as

shown at 34, and a plate 35 secured therein in any suitable manner, here shown by means of screws 36. In this manner I am able to neatly and securely inclose the various parts comprising my invention and thereby provide easy access thereto.

The operation of my invention thus far described is, briefly, as follows: When it is desired to turn on the electric bulb 5, the switch 4 of the socket 3 is operated inthe usual manner. With the operating screw 30 in the position shown in Fig. 2 of the drawings, the current from the source of power ,must of necessity travel through the resistance element 25, and from there to the lamp 5. It is obvious, therefore, that the degree of illumination given b the lamp will be at its lowest. If, thereafter, it is desired to increase the brilliance of the lamp 5, I accomplish this by rotating the screw 30 far enough to cause spring contacts 20 and 21 to 30 engage, thereby cutting out part of the resistance and consequently causing the electric current to flow through only a portion of the resistance element. If I thereafter rotate the operating screw 20 to cause spring contacts 20 and 21 to be depressed further to engage spring contact 22, I am enabled to'cut out all of the resistance and therefore again increase the brilliance of the lamp.

By referring now more particularly to Fig.8, I. will describe the circuit arrangement of my invention. Current is supplied through the wires A and B. I will trace the current through the wire B. In this case, current travels through the wire B to point 5 C, then through resistance elements D" and E to the point, F, through ,the electric bulb G, thence back through wire A tothe source of power. In this instance the set screw 30 has not come into operation, and contacts 20, 21 and 22 are not engaging one another.

Assume now that operating screw 30 has been rotated to force spring contact 20 into engagement with spring contact 21. The circuit will now be through the wire B to 1 5 the-point C, through resistance D, and from there through take-off wire H. It will then pass through spring contacts 21 and 20, through the wire I to the point F, thereafter through electric bulb G and back through wire A to the source of power. In this instance the resistance D only has come into the circuit, resistance E having been cut out by reason of the contact between spring contact members 21 and 20.

Assume now that the third position is reached. In this case operating screw 30 has been made to force spring contact members 20 and 21 further downwardly so as to engage spring contact member 22. The circuit is now through wire B to the point C, from there through wire J, through the spring contact members 22, 21 and 20, through wire I to the point F, and thereafter through the electric bulb G and back through wire A to the source of power. In

this instance it is evident that all of the resistance hasbeen cut out and the light will be at its brighest.

Refering now to Figs. 4 and 5, it will be the conventional candle type of fixture.

This type of the invention embodies a standard 37, adapted to simulate a candle. In this form the usual snap switch for turning on and ofi the electric light is located at the base of the standard 37 and provided with operating buttons 38, of the usual construction. The handle 39is formed of a piece of strap metal bent to provide a handle portion 40 and a securing portion 41. This handle member 39 may be secured to the base 1 in any suitable manner, but I have here shown it as secured by screws 42. In this form of my device, the operating screw 30 passes through the securing portion 41 of the handle 39, and I am enabled to dispense with the metal strap 28 as shown in Fi s. 1 and 2.

ngularly disposed ventilating o enings are provided in the upper face of t e base member 1 and are indicated by the numeral 43. These ventilating openings register with similar openings 44 formed in the base portion 45 of the lamp structure. In this form of my invention the radial openings 82 in the base 1 cooperate with the passage-ways formed by openings 43 and 44, to provide the proper ventilation for the recess 7 T will now refer to another form of my invention, illustrated in Fig. 6 of the drawings. In this form the post is made of a hollow? metal member 46, which rests in a circular recess 47, formed on the upper face of the base member 1. By providin the post 46 of the structure illustrated, am enabled to form the resistance coil of a spool-like structure 48, whichcan be slipped over the pipe 11 and thereby remove the resistance element from the recess 7 formed in the base member 1.

The resistance element 48 is of the usual spool type, and therefore no detailed description of the same need be made herein.

The metal post 46 is of sufficient diameterto provide an air space between the walls thereof and the resistance coil member 48. The upper face ofthe base member 46 is apertured, as at 49', to provide ventilation for the inside thereof. Ventilating openings 50 are provided to allow, communication between the recess 7 and the inside of the post member 46. The usual radial holes 32 are provided in the base member 1, and in this manner an efficient circulation is set up in order to completely dispose of any heat generated by the resistance coil 48.

From the foregoing it will be seen that the three forms of my invention all embody specifically the same general structure, in that I provide a plate carrying the spring contact members, which are controlled in each case by an operating screw. In the first two forms of my invention 1 have shown modifications.

the'resistance element as located in a recess formed in the base member 1, and in the third form of the invention I have placed this resistance element in the post portion of the structure.

By referrin tol ig. 7, it will be seen that the plate 17 w ich carries the spring contact members may be removed as a unit, and therefore this portion of my invention may be very easily assembled and inserted in the fixture. It is, of course, understood that the plate 17 may be formed of any insulating material, spch as porcelain, fiber, or the like.

The resistance element may also be easily attached in either form of my invention, and the usual standard type of resistance has been employed in my invention with great success.

By roviding a central pipe member l1 and using this member for uniting the post member to the base-1, l have provided a simple-but durable structure, which may be quickly and easily constructed and assembled. Also, the usual socket may be conveniently secured to the upper end of the pipe member 11.

As clearly shown in the drawings, 1 house most of the electrical elements. of my invention in a recess in the base, and cover the walls of this recess with asbestos, to insure a fire-proof construction. By closing up the aperture 7 with a plate, as shown at 35, l have provided means. for easily gaining access to this recess for renewing worn parts.

Various changes and modifications may be made to my invention without departin from the spirit and scope thereof, and specifically reserve the right to make such Having thus described my invention, what I claim is 1. A portable electric light fixture comprising a base, a vertical support projecting cuit, said base being provided with a chamber, a removable resistance unit being inter-' posed in sald circult and a separable means positioned in said chamber-for varying the amount of resistance through which the current to the light must pass, said means comprising a multiplicity of superimposed metal contacts, and a base plate upon which said contacts are mounted, said means be 'ing operatable from a point outside said chamber, substantially as described.

2 A portable electriclight fixture comprisingawooden base, a vertically disposed post projecting from said base, an electric light bulb supported on said post, a circuit including said light and a switch for controlling said circuit, said base being provided with a recess open at one side thereof,

the walls of said recess being covered with an insulating material, a resistance unit sup- 3. A portable electric light fixture, com-v prising a base, alvertically disposed post projecting from said base, an electric light socket, asnap switch and an electric light bulb supported in said socket, said base being provided with a recess, a series of resistance elements in said recess, a multiplicity of spring metal contacts arranged in said recess, a set screw supported on said base and adapted to successively force the spring metal contacts into engagement with one another, and a circuit whereby the successive engagement of said spring metal contacts cuts out a unit of said resistance and thereby controls the amount of current passing through said electric light bulb, as and for the purpose set forth.

4. A portable electric lamp comprising a base provided with a recess, said recess having its bottom side open, a vertically disposed post projecting from said base and an electric bulb supported upon the upper end of said post, a circuit including said electric light bulb and provided with a switch, a resistance unit removably secured within said recess, said resistance unit being interposed in said circuit, means for cutting in or out portions of said resistance unit comprising a removably secured insulating plate, a multiplicity of superimposed spring metal contacts secured upon said insulating plate, an operating screw supported upon said base and projecting into said recess to a point adjacent said spring contacts, to provide means forsuccessively causing said spring contacts to impinge upon one another, and a cover plate for closing the open side of said recess.

The foregoing specification signed at Washington, D. (3., this 16th day of March,

WIILIAM A. HARVEY. 

